Compiled Asterisk including res_fax [from make menuselect]. All seems to have been without event.Followed instructions to make res_fax_digium.so appropriate to the server (res_fax_digium-1.8.0_1.3.0-core2_64)... all properly licensed etc.

However, at load time the log shows:

Module 'res_fax.so' was not compiled with same compile-time options as this version of AsteriskModule 'res_fax.so' will not be initialized as it may cause instability.Module 'res_fax.so' could not be loaded